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NO SIGNAL but keyboard and mouse are working

By @bakabonpapa2021-06-22 23:53:18.415Z

Hi Michael.

I purchased TinyPilot voyager and set it up for a laptop recently.
It worked fine after my first setup.

But once I detached the device from the laptop and did attach to the laptop, TinyPilot started to fail to catch the screen (NO SIGNAL message in https://tinypilot page).
The keyboard input and mouse movement are OK through the page though.
I uploaded the log already.
Can you check it and tell me what is happening, and what should i do to solve it?

https://logs.tinypilotkvm.com/Aqp3IuVP

Thank you in advance.
bakabonpapa

  • 16 replies

There are 16 replies. Estimated reading time: 18 minutes

  1. B
    @bakabonpapa2021-06-23 00:04:39.861Z

    Addition.
    I plugined another monitor to the laptop, and could display the screen on the monitor.
    Maybe video output from the VGA is fine.

    1. B@bakabonpapa2021-06-23 08:05:52.522Z

      i changed to different pc attached with TinyPilot.
      Then, I connected TinyPilot to the original pc that had the screen problem.
      And now, the problem was solved and TinyPilot started to show the screen.
      Why?

      1. Michael Lynch @michael2021-06-23 20:02:53.815Z

        Hmm, that's difficult.

        It looks like the streaming service was failing to start:

        May 20 17:51:14 tinypilot ustreamer[576]: ================================================================================
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.184    stream] -- Device fd=9 opened
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.184    stream] -- Using input channel: 0
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.191    stream] -- Got new DV timings: resolution=1920x1080, pixclk=148500000
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.211    stream] -- Using resolution: 1920x1080
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.211    stream] -- Using pixelformat: UYVY
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.211    stream] -- Querying HW FPS changing is not supported
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.211    stream] -- Using IO method: MMAP
        May 20 17:51:14 tinypilot ustreamer[576]: -- INFO  [170.236    stream] -- Requested 5 device buffers, got 5
        May 20 17:51:14 tinypilot ustreamer[576]: -- ERROR [170.237    stream] -- Unable to start capturing: Invalid argument
        

        Did you change resolution on the target machine? Would you mind sharing the logs now that it's working?

        1. B@bakabonpapa2021-06-24 03:40:04.115Z

          Hi Michael.
          Thank you for your comment.

          Did you change resolution on the target machine?

          What I did, I wrote it concicely below

          1, After first arrival of TinyPilot, I setup it and it worked fine with Laptop A (1366x768).
          2, I detached TinyPilot from A, and shutdowned the device and A.
          3, I reattached A with the device, but the browserscreen showed "NO SIGNAL" as in the first post (collected first log here).
          4, I detached the device again, and attached it to another Laptop B (1920x1080), and it worked fine.
          5, After 4, I plugged the device into A and it recoverd the screen (Now)

          Would you mind sharing the logs now that it's working?

          I am now in above No.5, and collected the log again.
          https://logs.tinypilotkvm.com/ym97PX4N

          I like to know what happened for future failure.

          By the way, your product is very nice.

          Thank you.
          Bakabonpapa

          1. Michael Lynch @michael2021-06-24 18:08:39.012Z

            Did you restart the TinyPilot between machines? It might have been that the second machine's resolution somehow affected state and caused it to fail capturing video from the first machine.

            In the failing logs, we see TinyPilot trying to capture at 1920x1080:

            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.853    stream] -- Device fd=9 opened
            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.853    stream] -- Using input channel: 0
            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.860    stream] -- Got new DV timings: resolution=1920x1080, pixclk=148500000
            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.880    stream] -- Using resolution: 1920x1080
            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.880    stream] -- Using pixelformat: UYVY
            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.880    stream] -- Querying HW FPS changing is not supported
            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.880    stream] -- Using IO method: MMAP
            May 20 17:51:09 tinypilot ustreamer[576]: -- INFO  [164.903    stream] -- Requested 5 device buffers, got 5
            May 20 17:51:09 tinypilot ustreamer[576]: -- ERROR [164.904    stream] -- Unable to start capturing: Invalid argument
            

            In the successful logs, we see it capturing at 1366x768:

            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.686    stream] -- Device fd=9 opened
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.686    stream] -- Using input channel: 0
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.693    stream] -- Got new DV timings: resolution=1360x768, pixclk=85800960
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.714    stream] -- Using resolution: 1360x768
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.714    stream] -- Using pixelformat: UYVY
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.714    stream] -- Querying HW FPS changing is not supported
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.715    stream] -- Using IO method: MMAP
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.723    stream] -- Requested 5 device buffers, got 5
            Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO  [69835.728    stream] -- Capturing started
            

            I'm wondering if going from device B back to device A somehow breaks TinyPilot's video capture because it's "remembering" settings from the old device. A reboot of the TinyPilot should clear any persistent state.

            1. B@bakabonpapa2021-06-25 01:55:56.484Z

              After a certain amount of time of working fine from the last message,
              TinyPilot started to show "NO SIGNAL" again.
              I failed to tell you but the Laptop A is jump machine for Citrix virtual desktop.
              "NO SIGNAL" screen does not change between before and after connecting to the virtual desktop.

              Debug logs right now.
              https://logs.tinypilotkvm.com/qqhH4F6n

              Did you restart the TinyPilot between machines?

              I think so, I did several restarts or shutdown while trying to recover the screen.

              It might have been that the second machine's resolution somehow affected state and caused it to fail capturing video from the first machine.

              In the failing logs, we see TinyPilot trying to capture at 1920x1080:

              Jun 23 21:32:05 tinypilot ustreamer[1810]: -- INFO [69835.686 stream] -- Device fd=9
              I'm wondering if going from device B back to device A somehow breaks TinyPilot's video capture because it's "remembering" settings from the old device. A reboot of the TinyPilot should clear any persistent state.

              Can you tell me the steps to recover the screen when I fall into such state and having "NO SIGNAL" screen?
              Is Reboot enough?
              But mere rebooting is not working right now.

              Thank you.

              1. Michael Lynch @michael2021-06-28 18:34:25.089Z

                It seems to fail when the target machine outputs a resolution of 1920x1080, but it succeeds when the target machine uses 1366x768.

                Is it possible to change the resolution on the target machine to always output 1366x768?

                1. B@bakabonpapa2021-06-30 08:08:01.866Z

                  Is it possible to change the resolution on the target machine to always output 1366x768?

                  Yes, possible.
                  But how am I suppose to change configurations when switching between different PCs with different resolutions?

                  1. Michael Lynch @michael2021-06-30 18:53:58.572Z

                    Is this a problem on multiple machines? I thought that there was just one machine that failed to get a display consistently.

                    1. B@bakabonpapa2021-07-01 09:12:14.426Z

                      Is this a problem on multiple machines?
                      I thought that there was just one machine that failed to get a display consistently.

                      No. As you lined, this failure has been happening in just one machine (Laptop A).
                      As for Laptop B, TinyPilot seems to be working fine functioning after changing resolutions.
                      For Laptop A, the desktop is administered by AD and I cannot change the resolutions of the screen.

                      But, at the same time, i wanted to know if there is a "Official" steps for switching the device between PCs with different resolutions like this time.
                      Or is TinyPilot supposed to work "automatically" when switching?

                      1. Michael Lynch @michael2021-07-02 21:46:38.105Z2021-09-15 20:00:13.505Z

                        It should just work automatically, so I'm surprised it's getting stuck when switching machines.

                        One other thing you can try is to change the EDID. Those are the setting the TinyPilot uses to negotiate video settings with the target machine. To try an alternate EDID, run these commands:

                        EDID="/home/ustreamer/edids/tc358743-edid.hex"
                        
                        # Back up original EDID
                        cp --no-clobber "${EDID}" ~/tc358743-edid.hex.bak
                        
                        # Set a new EDID
                        echo -ne "" | sudo tee "${EDID}" && \
                          echo '00ffffffffffff0052628888008888882d1e0103' | sudo tee -a "${EDID}" && \
                          echo '800000780aee91a3544c99260f50542540000100' | sudo tee -a "${EDID}" && \
                          echo '0100010001000100010001010101d51b00505000' | sudo tee -a "${EDID}" && \
                          echo '19400820b80080001000001eec2c80a070381a40' | sudo tee -a "${EDID}" && \
                          echo '3020350040442100001e000000fc00546f736869' | sudo tee -a "${EDID}" && \
                          echo '62612d4832430a20000000fd00323d0f2e0f0000' | sudo tee -a "${EDID}" && \
                          echo '000000000000012a02030400de0d20a030581220' | sudo tee -a "${EDID}" && \
                          echo '30203400f0b400000018e01500a0400016303020' | sudo tee -a "${EDID}" && \
                          echo '3400000000000018b41400a050d0112030203500' | sudo tee -a "${EDID}" && \
                          echo '80d810000018ab22a0a050841a3030203600b00e' | sudo tee -a "${EDID}" && \
                          echo '1100001800000000000000000000000000000000' | sudo tee -a "${EDID}" && \
                          echo '0000000000000000000000000000000000000000' | sudo tee -a "${EDID}" && \
                          echo '00000000000000000000000000000045' | sudo tee -a "${EDID}" && \
                          sudo v4l2-ctl --device=/dev/video0 --set-edid=file="${EDID}" --fix-edid-checksums
                        

                        That setting will persist across reboots but not across updates. To make it permanent across updates, see this post.

                        If the new EDID causes problems, you can restore the original EDID with these commands:

                        # Do this only if the steps above cause issues.
                        EDID="/home/ustreamer/edids/tc358743-edid.hex"
                        sudo cp ~/tc358743-edid.hex.bak "${EDID}"
                        sudo chown ustreamer:ustreamer "${EDID}"
                        
    2. O
      In reply tobakabonpapa:
      Oriol Espanyol @Oriol2021-06-26 20:55:00.080Z

      Hi Michael,

      I also purchased TinyPilot voyager recently for my laptop and have the same problem as reported in this post.

      It work first time on the target laptop (Windows) using HDMI port. However, after first reboot of the TinyPilot I also get the "NO SIGNAL" message and keyboard and mouse sometimes working, sometimes not. I tried different configurations on the same laptop, using Docking Station, VGA to HDMI adapter, etc. Rebooted several times the TinyPilot and the laptop without success.
      When I try on different laptop (Mackbook Pro) it works fine (HDMI on USB-c hub). However, when I try back on Windows laptop it continues to show the "NO SIGNAL" message. Windows laptop works with additional screen via VGA and HDMI. So all hardware seems to be fine.

      Please advice.

      Oriol

      1. Michael Lynch @michael2021-06-28 19:26:49.307Z

        Sorry to hear you're running into this.

        Can you share your logs from System > Logs?

        Did it just work that first time on the Windows laptop or has it ever worked after that? Have you tried reducing the video resolution on the Windows laptop?

        1. OOriol Espanyol @Oriol2021-07-01 10:58:19.827Z

          Yes, please see below:

          https://logs.tinypilotkvm.com/PG7tiNPN

          Tried different display resolutions without success

          1. In reply tomichael:
            OOriol Espanyol @Oriol2021-07-01 11:34:00.802Z

            Some additional information and testing from my side:

            1. My Windows laptop has two video output ports: VGA and DisplayPort but no HDMI. I have two adapters, one for VGA to HDMI and another one for DisplayPort to HDMI.
              When using the VGA port and the corresponding adapter to HDMI, I could not manage to get the Tinypilot working even though I tried all resolution options from my laptop.
              When using the DisplayPort with the corresponding adapter, the Tinypilot works just fine.
            2. My MacOS laptop has also no HDMI output, but I have an adapter for USB-C to HDMI, and that seems to work fine as well.
            3. The Windows laptop works with the VGA output and VGA to HDMI adapter to a HDMI screen.
            1. Michael Lynch @michael2021-07-02 21:51:58.843Z

              Thanks for the additional explanation!

              So, it works with all scenarios except VGA to HDMI on the Windows laptop?

              It's possible that the VGA adaptor doesn't work with TinyPilot. Which brand VGA to HDMI adaptor is it? I rarely hear of VGA adaptors that don't work with TinyPilot, but a couple brands that I know work are FOINNEX and uoeos.

              You could also try the alternate EDID solution that I suggested in a thread above.